diff options
Diffstat (limited to 'include/linux/spinlock.h')
| -rw-r--r-- | include/linux/spinlock.h | 401 |
1 files changed, 284 insertions, 117 deletions
diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index 0e9682c9def..3f2867ff0ce 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -8,13 +8,13 @@ * * on SMP builds: * - * asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the + * asm/spinlock_types.h: contains the arch_spinlock_t/arch_rwlock_t and the * initializers * * linux/spinlock_types.h: * defines the generic type and initializers * - * asm/spinlock.h: contains the __raw_spin_*()/etc. lowlevel + * asm/spinlock.h: contains the arch_spin_*()/etc. lowlevel * implementations, mostly inline assembly code * * (also included on UP-debug builds:) @@ -34,7 +34,7 @@ * defines the generic type and initializers * * linux/spinlock_up.h: - * contains the __raw_spin_*()/etc. version of UP + * contains the arch_spin_*()/etc. version of UP * builds. (which are NOPs on non-debug, non-preempt * builds) * @@ -46,21 +46,22 @@ * linux/spinlock.h: builds the final spin_*() APIs. */ -#include <linux/config.h> +#include <linux/typecheck.h> #include <linux/preempt.h> #include <linux/linkage.h> #include <linux/compiler.h> +#include <linux/irqflags.h> #include <linux/thread_info.h> #include <linux/kernel.h> #include <linux/stringify.h> +#include <linux/bottom_half.h> +#include <asm/barrier.h> -#include <asm/system.h> /* * Must define these before including other files, inline functions need them */ -#define LOCK_SECTION_NAME \ - ".text.lock." __stringify(KBUILD_BASENAME) +#define LOCK_SECTION_NAME ".text..lock."KBUILD_BASENAME #define LOCK_SECTION_START(extra) \ ".subsection 1\n\t" \ @@ -72,177 +73,343 @@ #define LOCK_SECTION_END \ ".previous\n\t" -#define __lockfunc fastcall __attribute__((section(".spinlock.text"))) +#define __lockfunc __attribute__((section(".spinlock.text"))) /* - * Pull the raw_spinlock_t and raw_rwlock_t definitions: + * Pull the arch_spinlock_t and arch_rwlock_t definitions: */ #include <linux/spinlock_types.h> -extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock); - /* - * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them): + * Pull the arch_spin*() functions/declarations (UP-nondebug doesn't need them): */ -#if defined(CONFIG_SMP) +#ifdef CONFIG_SMP # include <asm/spinlock.h> #else # include <linux/spinlock_up.h> #endif -#define spin_lock_init(lock) do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0) -#define rwlock_init(lock) do { *(lock) = RW_LOCK_UNLOCKED; } while (0) +#ifdef CONFIG_DEBUG_SPINLOCK + extern void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name, + struct lock_class_key *key); +# define raw_spin_lock_init(lock) \ +do { \ + static struct lock_class_key __key; \ + \ + __raw_spin_lock_init((lock), #lock, &__key); \ +} while (0) -#define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock) +#else +# define raw_spin_lock_init(lock) \ + do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0) +#endif -/** - * spin_unlock_wait - wait until the spinlock gets unlocked - * @lock: the spinlock in question. - */ -#define spin_unlock_wait(lock) __raw_spin_unlock_wait(&(lock)->raw_lock) +#define raw_spin_is_locked(lock) arch_spin_is_locked(&(lock)->raw_lock) -/* - * Pull the _spin_*()/_read_*()/_write_*() functions/declarations: - */ -#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) -# include <linux/spinlock_api_smp.h> +#ifdef CONFIG_GENERIC_LOCKBREAK +#define raw_spin_is_contended(lock) ((lock)->break_lock) #else -# include <linux/spinlock_api_up.h> -#endif -#ifdef CONFIG_DEBUG_SPINLOCK - extern void _raw_spin_lock(spinlock_t *lock); -#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) - extern int _raw_spin_trylock(spinlock_t *lock); - extern void _raw_spin_unlock(spinlock_t *lock); - - extern void _raw_read_lock(rwlock_t *lock); - extern int _raw_read_trylock(rwlock_t *lock); - extern void _raw_read_unlock(rwlock_t *lock); - extern void _raw_write_lock(rwlock_t *lock); - extern int _raw_write_trylock(rwlock_t *lock); - extern void _raw_write_unlock(rwlock_t *lock); +#ifdef arch_spin_is_contended +#define raw_spin_is_contended(lock) arch_spin_is_contended(&(lock)->raw_lock) #else -# define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock) -# define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock) -# define _raw_spin_lock(lock) __raw_spin_lock(&(lock)->raw_lock) -# define _raw_spin_lock_flags(lock, flags) \ - __raw_spin_lock_flags(&(lock)->raw_lock, *(flags)) -# define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock) -# define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock) -# define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock) -# define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock) -# define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock) -# define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock) +#define raw_spin_is_contended(lock) (((void)(lock), 0)) +#endif /*arch_spin_is_contended*/ #endif -#define read_can_lock(rwlock) __raw_read_can_lock(&(rwlock)->raw_lock) -#define write_can_lock(rwlock) __raw_write_can_lock(&(rwlock)->raw_lock) +/* + * Despite its name it doesn't necessarily has to be a full barrier. + * It should only guarantee that a STORE before the critical section + * can not be reordered with a LOAD inside this section. + * spin_lock() is the one-way barrier, this LOAD can not escape out + * of the region. So the default implementation simply ensures that + * a STORE can not move into the critical section, smp_wmb() should + * serialize it with another STORE done by spin_lock(). + */ +#ifndef smp_mb__before_spinlock +#define smp_mb__before_spinlock() smp_wmb() +#endif /* - * Define the various spin_lock and rw_lock methods. Note we define these - * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various - * methods are defined as nops in the case they are not required. + * Place this after a lock-acquisition primitive to guarantee that + * an UNLOCK+LOCK pair act as a full barrier. This guarantee applies + * if the UNLOCK and LOCK are executed by the same CPU or if the + * UNLOCK and LOCK operate on the same lock variable. */ -#define spin_trylock(lock) __cond_lock(_spin_trylock(lock)) -#define read_trylock(lock) __cond_lock(_read_trylock(lock)) -#define write_trylock(lock) __cond_lock(_write_trylock(lock)) +#ifndef smp_mb__after_unlock_lock +#define smp_mb__after_unlock_lock() do { } while (0) +#endif -#define spin_lock(lock) _spin_lock(lock) -#define write_lock(lock) _write_lock(lock) -#define read_lock(lock) _read_lock(lock) +/** + * raw_spin_unlock_wait - wait until the spinlock gets unlocked + * @lock: the spinlock in question. + */ +#define raw_spin_unlock_wait(lock) arch_spin_unlock_wait(&(lock)->raw_lock) -#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) -#define spin_lock_irqsave(lock, flags) flags = _spin_lock_irqsave(lock) -#define read_lock_irqsave(lock, flags) flags = _read_lock_irqsave(lock) -#define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock) +#ifdef CONFIG_DEBUG_SPINLOCK + extern void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock); +#define do_raw_spin_lock_flags(lock, flags) do_raw_spin_lock(lock) + extern int do_raw_spin_trylock(raw_spinlock_t *lock); + extern void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock); #else -#define spin_lock_irqsave(lock, flags) _spin_lock_irqsave(lock, flags) -#define read_lock_irqsave(lock, flags) _read_lock_irqsave(lock, flags) -#define write_lock_irqsave(lock, flags) _write_lock_irqsave(lock, flags) +static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock) +{ + __acquire(lock); + arch_spin_lock(&lock->raw_lock); +} + +static inline void +do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags) __acquires(lock) +{ + __acquire(lock); + arch_spin_lock_flags(&lock->raw_lock, *flags); +} + +static inline int do_raw_spin_trylock(raw_spinlock_t *lock) +{ + return arch_spin_trylock(&(lock)->raw_lock); +} + +static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock) +{ + arch_spin_unlock(&lock->raw_lock); + __release(lock); +} #endif -#define spin_lock_irq(lock) _spin_lock_irq(lock) -#define spin_lock_bh(lock) _spin_lock_bh(lock) +/* + * Define the various spin_lock methods. Note we define these + * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The + * various methods are defined as nops in the case they are not + * required. + */ +#define raw_spin_trylock(lock) __cond_lock(lock, _raw_spin_trylock(lock)) -#define read_lock_irq(lock) _read_lock_irq(lock) -#define read_lock_bh(lock) _read_lock_bh(lock) +#define raw_spin_lock(lock) _raw_spin_lock(lock) -#define write_lock_irq(lock) _write_lock_irq(lock) -#define write_lock_bh(lock) _write_lock_bh(lock) +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# define raw_spin_lock_nested(lock, subclass) \ + _raw_spin_lock_nested(lock, subclass) -/* - * We inline the unlock functions in the nondebug case: - */ -#if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || !defined(CONFIG_SMP) -# define spin_unlock(lock) _spin_unlock(lock) -# define read_unlock(lock) _read_unlock(lock) -# define write_unlock(lock) _write_unlock(lock) +# define raw_spin_lock_nest_lock(lock, nest_lock) \ + do { \ + typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\ + _raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \ + } while (0) #else -# define spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock) -# define read_unlock(lock) __raw_read_unlock(&(lock)->raw_lock) -# define write_unlock(lock) __raw_write_unlock(&(lock)->raw_lock) +# define raw_spin_lock_nested(lock, subclass) _raw_spin_lock(lock) +# define raw_spin_lock_nest_lock(lock, nest_lock) _raw_spin_lock(lock) #endif -#if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || !defined(CONFIG_SMP) -# define spin_unlock_irq(lock) _spin_unlock_irq(lock) -# define read_unlock_irq(lock) _read_unlock_irq(lock) -# define write_unlock_irq(lock) _write_unlock_irq(lock) +#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) + +#define raw_spin_lock_irqsave(lock, flags) \ + do { \ + typecheck(unsigned long, flags); \ + flags = _raw_spin_lock_irqsave(lock); \ + } while (0) + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ + do { \ + typecheck(unsigned long, flags); \ + flags = _raw_spin_lock_irqsave_nested(lock, subclass); \ + } while (0) #else -# define spin_unlock_irq(lock) \ - do { __raw_spin_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0) -# define read_unlock_irq(lock) \ - do { __raw_read_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0) -# define write_unlock_irq(lock) \ - do { __raw_write_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0) +#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ + do { \ + typecheck(unsigned long, flags); \ + flags = _raw_spin_lock_irqsave(lock); \ + } while (0) #endif -#define spin_unlock_irqrestore(lock, flags) \ - _spin_unlock_irqrestore(lock, flags) -#define spin_unlock_bh(lock) _spin_unlock_bh(lock) +#else + +#define raw_spin_lock_irqsave(lock, flags) \ + do { \ + typecheck(unsigned long, flags); \ + _raw_spin_lock_irqsave(lock, flags); \ + } while (0) -#define read_unlock_irqrestore(lock, flags) \ - _read_unlock_irqrestore(lock, flags) -#define read_unlock_bh(lock) _read_unlock_bh(lock) +#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ + raw_spin_lock_irqsave(lock, flags) -#define write_unlock_irqrestore(lock, flags) \ - _write_unlock_irqrestore(lock, flags) -#define write_unlock_bh(lock) _write_unlock_bh(lock) +#endif + +#define raw_spin_lock_irq(lock) _raw_spin_lock_irq(lock) +#define raw_spin_lock_bh(lock) _raw_spin_lock_bh(lock) +#define raw_spin_unlock(lock) _raw_spin_unlock(lock) +#define raw_spin_unlock_irq(lock) _raw_spin_unlock_irq(lock) -#define spin_trylock_bh(lock) __cond_lock(_spin_trylock_bh(lock)) +#define raw_spin_unlock_irqrestore(lock, flags) \ + do { \ + typecheck(unsigned long, flags); \ + _raw_spin_unlock_irqrestore(lock, flags); \ + } while (0) +#define raw_spin_unlock_bh(lock) _raw_spin_unlock_bh(lock) -#define spin_trylock_irq(lock) \ +#define raw_spin_trylock_bh(lock) \ + __cond_lock(lock, _raw_spin_trylock_bh(lock)) + +#define raw_spin_trylock_irq(lock) \ ({ \ local_irq_disable(); \ - _spin_trylock(lock) ? \ + raw_spin_trylock(lock) ? \ 1 : ({ local_irq_enable(); 0; }); \ }) -#define spin_trylock_irqsave(lock, flags) \ +#define raw_spin_trylock_irqsave(lock, flags) \ ({ \ local_irq_save(flags); \ - _spin_trylock(lock) ? \ + raw_spin_trylock(lock) ? \ 1 : ({ local_irq_restore(flags); 0; }); \ }) +/** + * raw_spin_can_lock - would raw_spin_trylock() succeed? + * @lock: the spinlock in question. + */ +#define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock)) + +/* Include rwlock functions */ +#include <linux/rwlock.h> + +/* + * Pull the _spin_*()/_read_*()/_write_*() functions/declarations: + */ +#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) +# include <linux/spinlock_api_smp.h> +#else +# include <linux/spinlock_api_up.h> +#endif + +/* + * Map the spin_lock functions to the raw variants for PREEMPT_RT=n + */ + +static inline raw_spinlock_t *spinlock_check(spinlock_t *lock) +{ + return &lock->rlock; +} + +#define spin_lock_init(_lock) \ +do { \ + spinlock_check(_lock); \ + raw_spin_lock_init(&(_lock)->rlock); \ +} while (0) + +static inline void spin_lock(spinlock_t *lock) +{ + raw_spin_lock(&lock->rlock); +} + +static inline void spin_lock_bh(spinlock_t *lock) +{ + raw_spin_lock_bh(&lock->rlock); +} + +static inline int spin_trylock(spinlock_t *lock) +{ + return raw_spin_trylock(&lock->rlock); +} + +#define spin_lock_nested(lock, subclass) \ +do { \ + raw_spin_lock_nested(spinlock_check(lock), subclass); \ +} while (0) + +#define spin_lock_nest_lock(lock, nest_lock) \ +do { \ + raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock); \ +} while (0) + +static inline void spin_lock_irq(spinlock_t *lock) +{ + raw_spin_lock_irq(&lock->rlock); +} + +#define spin_lock_irqsave(lock, flags) \ +do { \ + raw_spin_lock_irqsave(spinlock_check(lock), flags); \ +} while (0) + +#define spin_lock_irqsave_nested(lock, flags, subclass) \ +do { \ + raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \ +} while (0) + +static inline void spin_unlock(spinlock_t *lock) +{ + raw_spin_unlock(&lock->rlock); +} + +static inline void spin_unlock_bh(spinlock_t *lock) +{ + raw_spin_unlock_bh(&lock->rlock); +} + +static inline void spin_unlock_irq(spinlock_t *lock) +{ + raw_spin_unlock_irq(&lock->rlock); +} + +static inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags) +{ + raw_spin_unlock_irqrestore(&lock->rlock, flags); +} + +static inline int spin_trylock_bh(spinlock_t *lock) +{ + return raw_spin_trylock_bh(&lock->rlock); +} + +static inline int spin_trylock_irq(spinlock_t *lock) +{ + return raw_spin_trylock_irq(&lock->rlock); +} + +#define spin_trylock_irqsave(lock, flags) \ +({ \ + raw_spin_trylock_irqsave(spinlock_check(lock), flags); \ +}) + +static inline void spin_unlock_wait(spinlock_t *lock) +{ + raw_spin_unlock_wait(&lock->rlock); +} + +static inline int spin_is_locked(spinlock_t *lock) +{ + return raw_spin_is_locked(&lock->rlock); +} + +static inline int spin_is_contended(spinlock_t *lock) +{ + return raw_spin_is_contended(&lock->rlock); +} + +static inline int spin_can_lock(spinlock_t *lock) +{ + return raw_spin_can_lock(&lock->rlock); +} + +#define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock) + /* * Pull the atomic_t declaration: * (asm-mips/atomic.h needs above definitions) */ -#include <asm/atomic.h> +#include <linux/atomic.h> /** * atomic_dec_and_lock - lock on reaching reference count zero * @atomic: the atomic counter * @lock: the spinlock in question + * + * Decrements @atomic by 1. If the result is 0, returns true and locks + * @lock. Returns false for all other cases. */ extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock); #define atomic_dec_and_lock(atomic, lock) \ - __cond_lock(_atomic_dec_and_lock(atomic, lock)) - -/** - * spin_can_lock - would spin_trylock() succeed? - * @lock: the spinlock in question. - */ -#define spin_can_lock(lock) (!spin_is_locked(lock)) + __cond_lock(lock, _atomic_dec_and_lock(atomic, lock)) #endif /* __LINUX_SPINLOCK_H */ |